It is the bleeding within the skull. Subtypes are intracerebral bleeds, subarachnoid bleeds, epidural bleeds and subdural bleeds. Intracranial hemorrhage is a serious medical emergency because the buildup of blood within the skull can lead to increase an intracranial pressure, which can crush delicate brain tissues or limit its blood supply. Intracranial bleeding occurs when a vessel within the skull is leaked or ruptured.